RANK Ligand-induced Elevation of Cytosolic Ca2+ Accelerates Nuclear Translocation of Nuclear Factor κB in Osteoclasts

RANK ligand (RANKL) induces activation of NFκB, enhancing the formation, resorptive activity, and survival of osteoclasts. Ca2+ transduces many signaling events, however, it is not known whether the actions of RANKL involve Ca2+ signaling. We investigated the effects of RANKL on rat osteoclasts using microspectrofluorimetry and patch clamp. RANKL induced transient elevation of cytosolic free Ca2+concentration ([Ca2+]i) to maxima 220 nm above basal, resulting in activation of Ca2+-dependent K+ current. RANKL elevated [Ca2+]i in Ca2+-containing and Ca2+-free media, and responses were prevented by the phospholipase C inhibitor U73122. Suppression of [Ca2+]i elevation using the intracellular Ca2+ chelator 1,2-bis(O-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA) abolished the ability of RANKL to enhance osteoclast survival. Using immunofluorescence, NFκB was found predominantly in the cytosol of untreated osteoclasts. RANKL induced transient translocation of NFκB to the nuclei, which was maximal at 15 min.U73122 or BAPTA delayed nuclear translocation of NFκB. Delays were also observed upon inhibition of calcineurin or protein kinase C. We conclude that RANKL acts through phospholipase C to release Ca2+ from intracellular stores, accelerating nuclear translocation of NFκB and promoting osteoclast survival. Such cross-talk between NFκB and Ca2+ signaling provides a novel mechanism for the temporal regulation of gene expression in osteoclasts and other cell types. RANK ligand (RANKL) induces activation of NFκB, enhancing the formation, resorptive activity, and survival of osteoclasts. Ca2+ transduces many signaling events, however, it is not known whether the actions of RANKL involve Ca2+ signaling. We investigated the effects of RANKL on rat osteoclasts using microspectrofluorimetry and patch clamp. RANKL induced transient elevation of cytosolic free Ca2+concentration ([Ca2+]i) to maxima 220 nm above basal, resulting in activation of Ca2+-dependent K+ current. RANKL elevated [Ca2+]i in Ca2+-containing and Ca2+-free media, and responses were prevented by the phospholipase C inhibitor U73122. Suppression of [Ca2+]i elevation using the intracellular Ca2+ chelator 1,2-bis(O-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA) abolished the ability of RANKL to enhance osteoclast survival. Using immunofluorescence, NFκB was found predominantly in the cytosol of untreated osteoclasts. RANKL induced transient translocation of NFκB to the nuclei, which was maximal at 15 min.U73122 or BAPTA delayed nuclear translocation of NFκB. Delays were also observed upon inhibition of calcineurin or protein kinase C. We conclude that RANKL acts through phospholipase C to release Ca2+ from intracellular stores, accelerating nuclear translocation of NFκB and promoting osteoclast survival. Such cross-talk between NFκB and Ca2+ signaling provides a novel mechanism for the temporal regulation of gene expression in osteoclasts and other cell types. receptor activator of NFκB acetoxymethyl ester activator protein 1 cytosolic free Ca2+concentration nuclear factor κB inhibitor of NFκB IκB kinase intermediate conductance Ca2+-dependent K+ current osteoprotegerin phospholipase C protein kinase C receptor activator of NFκB ligand tumor necrosis factor receptor-associated factor phosphate-buffered saline 1,2-bis(O-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid RANK1 ligand (RANKL) is a member of the tumor necrosis factor superfamily that plays an essential role in osteoclastogenesis, as well as the activation and survival of mature osteoclasts. This factor is expressed on osteoblasts, stromal cells, B-lymphoid lineage cells, and activated T-cells as a transmembrane ligand and it also exists in a biologically active soluble form (1Manabe N. Kawaguchi H. Chikuda H. Miyaura C. Inada M. Nagai R. Nabeshima Y. Nakamura K. Sinclair A.M. Scheuermann R.H. Kuro-o M. J. Immunol. 2001; 167: 2625-2631Google Scholar, 2Lacey D.L. Timms E. Tan H.L. Kelley M.J. Dunstan C.R. Burgess T. Elliott R. Colombero A. Elliott G. Scully S. Hsu H. Sullivan J. Hawkins N. Davy E. Capparelli C. Eli A. Qian Y.X. Kaufman S. Sarosi I. Shalhoub V. Senaldi G. Guo J. Delaney J. Boyle W.J. Cell. 1998; 93: 165-176Google Scholar, 3Yasuda H. Shima N. Nakagawa N. Yamaguchi K. Kinosaki M. Mochizuki S. Tomoyasu A. Yano K. Goto M. Murakami A. Tsuda E. Morinaga T. Higashio K. Udagawa N. Takahashi N. Suda T. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 3597-3602Google Scholar). RANKL acts through its receptor RANK, which is expressed on osteoclast precursors, mature osteoclasts, as well as dendritic cells (4Hofbauer L.C. Eur. J. Endocrinol. 1999; 141: 195-210Google Scholar). Osteoprotegerin (OPG) is a soluble decoy receptor, which binds RANKL and blocks its interaction with RANK (4Hofbauer L.C. Eur. J. Endocrinol. 1999; 141: 195-210Google Scholar). Signaling through RANK involves the recruitment of cytosolic tumor necrosis factor receptor-associated factors (TRAFs) 1, 2, 3, 5, and 6, which in turn activate multiple signaling pathways (5Wong B.R. Josien R. Lee S.Y. Vologodskaia M. Steinman R.M. Choi Y. J. Biol. Chem. 1998; 273: 28355-28359Google Scholar, 6Galibert L. Tometsko M.E. Anderson D.M. Cosman D. Dougall W.C. J. Biol. Chem. 1998; 273: 34120-34127Google Scholar, 7Darnay B.G. Haridas V. Ni J. Moore P.A. Aggarwal B.B. J. Biol. Chem. 1998; 273: 20551-20555Google Scholar). For example, the association of RANK with TRAF2 induces activation of c-Jun N-terminal kinase, which leads to phosphorylation of c-Jun and activation of AP-1 (7Darnay B.G. Haridas V. Ni J. Moore P.A. Aggarwal B.B. J. Biol. Chem. 1998; 273: 20551-20555Google Scholar, 8Lee Z.H. Kwack K. Kim K.K. Lee S.H. Kim H.H. Mol. Pharmacol. 2000; 58: 1536-1545Google Scholar, 9Zhang Y.H. Heulsmann A. Tondravi M.M. Mukherjee A. Abu-Amer Y. J. Biol. Chem. 2001; 276: 563-568Google Scholar). TRAF6 has been implicated in activation of the nonreceptor tyrosine kinase c-Src and the transcription factor NFκB (10Wong B.R. Besser D. Kim N. Arron J.R. Vologodskaia M. Hanafusa H. Choi Y. Mol Cell. 1999; 4: 1041-1049Google Scholar, 11Darnay B.G. Ni J. Moore P.A. Aggarwal B.B. J. Biol. Chem. 1999; 274: 7724-7731Google Scholar). NFκB transcription factors are dimers of the five mammalian NFκB proteins: p65 (RelA), RelB, c-Rel, p50 (NFκB1), and p52 (NFκB2). NFκB regulates the expression of a large number of genes involved in cell survival as well as in cellular responses to inflammation and stress (12Karin M. Ben-Neriah Y. Annu. Rev. Immunol. 2000; 18: 621-663Google Scholar, 13Mak T.W. Yeh W.C. Arthritis Res. 2002; 4: S243-S252Google Scholar). Typically, NFκB exists as a heterodimer of p50 and p65 (12Karin M. Ben-Neriah Y. Annu. Rev. Immunol. 2000; 18: 621-663Google Scholar). NFκB is retained in the cytoplasm complexed with inhibitory proteins IκBs. RANK signaling involves activation of NFκB-inducing kinase, leading to activation of IκB kinases (IKK) α and β, which in turn phosphorylate serine residues on IκB, targeting it for degradation in the proteasome (5Wong B.R. Josien R. Lee S.Y. Vologodskaia M. Steinman R.M. Choi Y. J. Biol. Chem. 1998; 273: 28355-28359Google Scholar, 11Darnay B.G. Ni J. Moore P.A. Aggarwal B.B. J. Biol. Chem. 1999; 274: 7724-7731Google Scholar, 14Wei S. Teitelbaum S.L. Wang M.W. Ross F.P. Endocrinology. 2001; 142: 1290-1295Google Scholar). IκB degradation exposes the NFκB nuclear localization sequence, permitting its nuclear import. Within the nucleus, NFκB acts in concert with other transcription factors to regulate gene expression, with termination of the signal caused by binding of IκB (15Sun S.C. Ganchi P.A. Ballard D.W. Greene W.C. Science. 1993; 259: 1912-1915Google Scholar). NFκB is essential for osteoclastogenesis, as disruption of both p50 and p52 subunits of NFκB leads to an osteopetrotic phenotype, because of impaired osteoclast differentiation (16Iotsova V. Caamano J. Loy J. Yang Y. Lewin A. Bravo R. Nat. Med. 1997; 3: 1285-1289Google Scholar). Interaction of RANKL with RANK is crucial for osteoclast function, however, there are gaps in our understanding of the signaling events leading to activation of NFκB in response to RANKL. Although interaction of RANK with TRAF6 is necessary and sufficient to activate NFκB, dominant negative forms of TRAF molecules are unable to completely block NFκB activation, suggesting that a TRAF-independent pathway is also involved (5Wong B.R. Josien R. Lee S.Y. Vologodskaia M. Steinman R.M. Choi Y. J. Biol. Chem. 1998; 273: 28355-28359Google Scholar, 11Darnay B.G. Ni J. Moore P.A. Aggarwal B.B. J. Biol. Chem. 1999; 274: 7724-7731Google Scholar). Because Ca2+-sensitive effectors such as calcineurin and protein kinase C (PKC) mediate NFκB activation in T lymphocytes and monocytic cell lines (17Steffan N.M. Bren G.D. Frantz B. Tocci M.J. O'Neill E.A. Paya C.V. J. Immunol. 1995; 155: 4685-4691Google Scholar, 18Trushin S.A. Pennington K.N. Algeciras-Schimnich A. Paya C.V. J. Biol. Chem. 1999; 274: 22923-22931Google Scholar), we considered the possible role of Ca2+ in the activation of NFκB by RANKL in osteoclasts. We tested the hypothesis that RANKL signaling in osteoclasts involves elevation of [Ca2+]i, and examined the role of cytosolic Ca2+ in cell survival and activation of NFκB. Classical biochemical approaches for studying osteoclasts are limited because of difficulty in isolating cells in sufficient number and purity. Furthermore, osteoclasts are terminally differentiated, and therefore do not proliferate in culture. We overcame these restrictions by studying authentic osteoclasts using single-cell techniques: microspectrofluorimetry and patch clamp to study changes in [Ca2+]i and membrane currents, and immunofluorescence to assess nuclear translocation of NFκB. We report that RANKL stimulates phospholipase C (PLC) leading to release of Ca2+ from intracellular stores, transient elevation of [Ca2+]i, and activation of Ca2+-dependent K+ current. The effect of RANKL on osteoclast survival was found to be dependent on elevation of [Ca2+]i. Moreover, nuclear translocation of NFκB was slowed when elevation of Ca2+was suppressed or when calcineurin or PKC were inhibited. Thus, phospholipase C and Ca2+ signaling are revealed to be important regulators of NFκB activation and osteoclast survival. Osteoclasts were isolated from the long bones of neonatal Wistar rats or neonatal New Zealand White rabbits as described previously (19Naemsch L.N. Dixon S.J. Sims S.M. J. Biol. Chem. 2001; 276: 39107-39114Google Scholar). Briefly, long bones were dissected free of soft tissue and cut with a scalpel to release bone fragments into 2–3 ml of osteoclast culture medium that consisted of Medium 199 buffered with 25 mm HEPES and HCO3− (Invitrogen, Burlington, Ontario) supplemented with 15% heat-inactivated fetal bovine serum and 1% 25 were by a and on or culture osteoclasts were at in for 1 with phosphate-buffered saline to cells and in medium for at 1 we the number of rat osteoclasts in culture at of of RANKL or and at osteoclasts were at in for culture medium was and cells were at in for to The of cells were from using in with mm for at with from K. T. H. K. T. M. N. Y. M. Res. Scholar). Osteoclasts were by the of or nuclei, and by osteoclast were as large in cells that were in a of and a cells with and for the osteoclast acid were by the on of the of RANKL and at the to the of were by and RANKL at the to a and a was from and were from in and at the of and were in and to the or medium the ester and were from and were in Osteoclasts were with the BAPTA or by in medium Medium 199 buffered with HEPES supplemented with 15% fetal bovine serum and 1% or for at and were from and were in [Ca2+]i of rat osteoclasts and osteoclast was using on were with for at in were in a on the of a and at with to with The of at nm with of and nm was using a as described previously Dixon S.J. Sims S.M. J. 2001; Scholar). RANKL was to cells by from a cells were with a Ca2+-free supplemented with mm The cell patch clamp was to membrane as described previously J. Dixon S.J. Sims S.M. J. 1997; Scholar). to with was were in at were with and at using Osteoclasts on were with or RANKL in osteoclast culture medium at and at the with in with in in and with 1% serum in for at to p65 number was in and at by in and for at with in with in were on with and examined using a We localization of in osteoclasts on Osteoclasts were for nuclear localization of or that of the are as as of cells or as with the number of osteoclasts for Ca2+ or or the number of cell for immunofluorescence were by of for by a or and as at were by using were were the osteoclasts were with and Ca2+ was by Osteoclasts [Ca2+]i of Osteoclasts to soluble RANKL with elevation of [Ca2+]i, which and in the of RANKL. of to [Ca2+]i be by of RANKL 1 the responses were in responses were observed when osteoclasts were with Moreover, the ability of RANKL to [Ca2+]i in osteoclasts that were to multiple of RANKL The of osteoclasts to RANKL with elevation of [Ca2+]i was dependent on the of RANKL 1 [Ca2+]i were by of RANKL as as The of osteoclasts to RANKL at with effects at the of the Ca2+ were was observed of RANKL elevated [Ca2+]i to of 220 on 15 osteoclasts of We also changes in Ca2+ upon of RANKL to rat osteoclast at of 1 RANKL caused elevation of [Ca2+]i in of osteoclast of osteoclasts, tested in the with elevation of a negative we tested the responses of stromal cells and found that of the cells tested to RANKL. Thus, a of osteoclast to RANKL with elevation of [Ca2+]i, the of was that of mature osteoclasts. were using osteoclasts. We investigated the of Ca2+ to elevation of [Ca2+]i in osteoclasts. RANKL Ca2+ of in Ca2+-containing and Ca2+-free with release of intracellular and from involves of We previously that the blocks elevation of [Ca2+]i in osteoclasts Dixon S.J. Sims S.M. J. 2001; Scholar). of osteoclasts with for abolished the of [Ca2+]i, RANKL [Ca2+]i in the of the or 2, C these that RANKL through leading to release of Ca2+ from intracellular and transient elevation of [Ca2+]i. are in to that RANKL caused elevation of [Ca2+]i in osteoclasts C. Wang H. M. 1999; Scholar). was to the effect of RANKL on [Ca2+]i in osteoclasts. and osteoclasts intermediate conductance Ca2+-dependent K+ Dixon S.J. Sims S.M. 2001; Scholar). Because a of rat osteoclasts current J. Dixon S.J. Sims S.M. J. 1997; Scholar), we patch clamp to the effects of RANKL on membrane of osteoclasts, which the current L.N. Sims S.M. Dixon S.J. J. Sci. 1999; Scholar). were at and were RANKL current a of of osteoclasts with current at were from the current to of RANKL was by the K+ current that has been previously in osteoclasts of the current from that at the of the response to RANKL that the current was and to current K+ current has been previously to of [Ca2+]i in osteoclasts J. Dixon S.J. Sims S.M. J. 1997; Scholar). Thus, current activation of Ca2+-dependent K+ because of of [Ca2+]i. the that RANKL induces elevation of [Ca2+]i in osteoclasts. was previously that RANKL osteoclast survival in D.L. Tan H.L. J. Kaufman S. G. A. Scully S. T. Kelley M. Burgess Boyle W.J. J. 2000; Scholar). We investigated the role of Ca2+ in using the intracellular Ca2+ chelator for of Ca2+ by we which on osteoclasts leading to release of Ca2+ from intracellular and elevation of [Ca2+]i Dixon S.J. Sims S.M. J. 2001; Scholar). Osteoclasts were with to with of and with We that with for at was for elevation of [Ca2+]i induced by We these BAPTA was in elevation of [Ca2+]i the role of [Ca2+]i in osteoclast cells were with or The medium was and osteoclasts were with RANKL or at for The number of osteoclasts at was expressed as a of the number of osteoclasts in the RANKL the number of osteoclasts that BAPTA suppressed effect of not osteoclast survival in the of RANKL Thus, elevation of [Ca2+]i to be necessary for RANKL to osteoclast survival. NFκB is of the effectors of RANK signaling and activation of NFκB cell survival in many cell T.W. Yeh W.C. Arthritis Res. 2002; 4: S243-S252Google Scholar, D.L. Tan H.L. J. Kaufman S. G. A. Scully S. T. Kelley M. Burgess Boyle W.J. J. 2000; Scholar). we investigated the possible of the pathway in the nuclear translocation of NFκB in osteoclasts. of NFκB was at the single-cell using immunofluorescence to the of the p65 of NFκB. the of untreated rat or osteoclasts, NFκB was in the cytoplasm for the of the a of osteoclasts, RANKL induced of NFκB to the nuclei, to the a osteoclast translocation of NFκB was of and translocation was by 15 with of osteoclasts nuclear localization of NFκB with 1% in untreated osteoclasts a role of the signaling we the of NFκB translocation in osteoclasts with the inhibitor which [Ca2+]i induced by RANKL. delayed translocation of NFκB from the cytoplasm to the in response to RANKL. cells, translocation was delayed of RANKL 15 in with RANKL not the of osteoclasts nuclear translocation of NFκB in response to RANKL in in on from a of which not or block elevation of [Ca2+]i 2, C effect on translocation of NFκB Thus, we that RANKL signaling through the of NFκB We examined whether of intracellular Ca2+ using BAPTA the of translocation of NFκB. Using we found that BAPTA delayed nuclear translocation of NFκB induced by RANKL 6, on from osteoclasts, translocation was observed with RANKL in cells with RANKL of cells with BAPTA the of osteoclasts nuclear localization of NFκB at 15 the of cells nuclear localization at was in Furthermore, BAPTA the of osteoclasts nuclear translocation of NFκB in response to with RANKL for osteoclasts for the of BAPTA not NFκB of in release of because of the degradation of the acetoxymethyl ester whether these degradation NFκB we examined cells with that the as is as a Ca2+ chelator at cells with not the or of NFκB translocation 6, possible effects of the degradation these that elevation of [Ca2+]i nuclear translocation of NFκB. We examined the role of a known to to activation of NFκB in other the The calcineurin of suppressed the NFκB translocation with effect at on from The calcineurin suppressed NFκB translocation at to of effect at 15 of are with elevation of [Ca2+]i transient activation of which in turn activation of NFκB. activation leads to the of Ca2+ and both of which to activation of other PKC activate IκB translocation of NFκB (12Karin M. Ben-Neriah Y. Annu. Rev. Immunol. 2000; 18: 621-663Google Scholar). osteoclasts, the PKC inhibitor of RANKL suppressed NFκB translocation at and 15 on from with effect at the that not effect on NFκB translocation and of at and 15 are with a role for activated of phospholipase in the effects of RANKL on NFκB. The effects of and were at however, the calcineurin inhibitor effect at 15 on from NFκB translocation at in with with was of in with or and effect at 15 in the of and was of in osteoclasts with these that calcineurin and PKC are effectors of RANK that activation of NFκB. We that RANKL induces transient elevation of [Ca2+]i in osteoclasts because of activation of and release of Ca2+ from intracellular The of [Ca2+]i stimulates Ca2+-dependent K+ nuclear translocation of NFκB, and osteoclast for and RANK signaling in osteoclasts. effects of RANKL on [Ca2+]i were observed at with maximal actions at are in with the for the of by RANKL H. Sarosi I. Tan H.L. Timms E. Capparelli C. S. G. A. A. Dunstan C.R. D.L. T.W. Boyle W.J. 1999; Scholar, J. Sarosi I. S. Capparelli C. Tan H.L. S. Elliott R. Scully S. G. Kaufman S. S.C. Y. J. L. K. J. Hsu H. Dunstan C.R. D.L. Boyle W.J. Proc. Natl. Acad. Sci. U. S. A. 2000; Scholar), suggesting that elevation of [Ca2+]i is by Moreover, prevented elevation of [Ca2+]i, possible of RANKL multiple of RANK signaling is to be by interaction of osteoclasts and with cells RANKL cells, osteoblasts, and of osteoclasts to multiple from cells, to temporal and of RANKL that RANK signaling in osteoclasts involves is activated by factor receptor tyrosine kinases or nonreceptor tyrosine kinases to M.J. Rev. 2000; Scholar). RANK and TRAF6 and activate the nonreceptor tyrosine kinase c-Src (10Wong B.R. Besser D. Kim N. Arron J.R. Vologodskaia M. Hanafusa H. Choi Y. Mol Cell. 1999; 4: 1041-1049Google Scholar), which to to the in osteoclasts, as was for cells Lee Kim Kim Choi Y. Kim Lee S.Y. J. Biol. Chem. 2002; Scholar). disruption of in an osteopetrotic because of resorptive of osteoclasts C. R. A. Cell. Scholar). is not impaired in a for c-Src signaling in osteoclasts and with these we observed that is in mature osteoclasts in Furthermore, been to because of osteoclasts Yeh W.C. Sarosi I. C. A. S. Capparelli C. G. Kaufman S. A. A. A. T. D.L. Dunstan C.R. Boyle W.J. T.W. 1999; Scholar), also suggesting between RANKL signaling in and mature osteoclasts. was found to be impaired in TRAF6 A. S. S. T. S. K. K. Nakamura K. M. T. J. 1999; 4: Scholar), the of the role for pathways in and activation of in other cell cytosolic Ca2+ plays important in a number of osteoclast We that RANKL the intermediate conductance Ca2+-dependent K+ current in osteoclasts. that elevation of [Ca2+]i in activation of current J. Dixon S.J. Sims S.M. J. 1997; Scholar), our to elevation of [Ca2+]i. the membrane resulting from activation of the of and the for of a in T cell signaling H. M.J. H. C.R. J. Biol. Chem. 2001; 276: Scholar). an important role in osteoclast that are expressed in rat osteoclasts the of cells J. Dixon S.J. Sims S.M. J. 1997; Scholar). Ca2+ also regulates through Ca2+-dependent such as that in osteoclast M. N. M. U. D. J. Biol. 2000; Scholar). in multiple effects in osteoclasts. we found that elevation of [Ca2+]i is necessary for RANKL to osteoclast survival. Although that elevation of [Ca2+]i in osteoclasts leads to inhibition of M. L. J. Res. 1999; Scholar), implicated Ca2+-dependent pathways in promoting osteoclast N. K. M. T. S. Y. M. T. T. J. Biol. Chem. 2002; Scholar). osteoclasts, as in other the effects of [Ca2+]i elevation upon the and of the Ca2+ signal as well as its with other signaling NFκB is a transcription factor that cell survival in many T.W. Yeh W.C. Arthritis Res. 2002; 4: S243-S252Google Scholar). the we that Ca2+ signaling nuclear translocation of NFκB. be of [Ca2+]i to be to activate NFκB in osteoclasts. such as which to the of release Dixon S.J. Sims S.M. J. 2001; Scholar), do not activate NFκB in osteoclasts. J. Dixon and S. M. elevation of [Ca2+]i is to activate NFκB in cells S.A. Pennington K.N. Algeciras-Schimnich A. Paya C.V. J. Biol. Chem. 1999; 274: 22923-22931Google Scholar, J. Biol. Chem. 2001; 276: Scholar). to in concert with other signaling pathways to activation of NFκB in osteoclasts. RANK signaling involves a of events, with the recruitment of leading to activation of NFκB-inducing kinase and the (5Wong B.R. Josien R. Lee S.Y. Vologodskaia M. Steinman R.M. Choi Y. J. Biol. Chem. 1998; 273: 28355-28359Google Scholar, 11Darnay B.G. Ni J. Moore P.A. Aggarwal B.B. J. Biol. Chem. 1999; 274: 7724-7731Google Scholar, 14Wei S. Teitelbaum S.L. Wang M.W. Ross F.P. Endocrinology. 2001; 142: 1290-1295Google Scholar). of the phosphorylation of IκB, accelerating translocation of NFκB to the Ca2+ to of the and is to be activated by Ca2+-dependent of T cell receptor calcineurin and PKC S.A. Pennington K.N. Algeciras-Schimnich A. Paya C.V. J. Biol. Chem. 1999; 274: 22923-22931Google Scholar). We in osteoclasts that RANK signaling involves these is a that is by The and and the of calcineurin J. Biol. Chem. 2001; 276: Scholar). We found that both of these delayed the of NFκB activation in osteoclasts, maximal actions of the that effects are by The actions of calcineurin were to which be by the that elevation of [Ca2+]i in response to RANKL is to activation of to previously observed inhibitory effects of on in V. D.W. Scholar). of also leads to activation of the of we a inhibitor of the and novel PKC and using the V. of PKC also caused in NFκB activation, with in maximal to the calcineurin PKC inhibition in a in NFκB which the for of it that of NFκB activation involve the of signaling Moreover, the effects of calcineurin and PKC were and in to the effects of a role for Ca2+ in the of NFκB Because the of multiple transcription factors regulates expression of the of activation is of the temporal of NFκB activation has been to in gene expression A. A. D. Science. 2002; Scholar). concert with other transcription NFκB cell survival and the expression of genes and molecules (12Karin M. Ben-Neriah Y. Annu. Rev. Immunol. 2000; 18: 621-663Google Scholar, 13Mak T.W. Yeh W.C. Arthritis Res. 2002; 4: S243-S252Google Scholar, W.C. J. Med. 1998; Scholar). RANK also which with other transcription factors and NFκB, to regulation of transcription Y. 2001; Scholar, Y. Mol. 2000; Scholar). c-Jun and been to with the p65 of NFκB, enhancing both the κB and AP-1 response B. Ballard D.W. Greene W.C. J. 1993; Scholar). NFκB with the transcription and other regulators to gene expression S.Y. S.Y. Choi J. Lee Lee Mol. Endocrinol. 2000; Scholar). the of NFκB and other transcription factors at of the of transcription and gene Thus, responses upon the of activation of NFκB and other transcription factors by RANKL or by other signaling molecules on the the of osteoclast survival on is because of changes in the of NFκB translocation or because of the activation of other Ca2+-dependent pathways is to be the cross-talk between NFκB and Ca2+ signaling provides a novel mechanism for the temporal regulation of NFκB and gene expression in osteoclasts and other cell types. We for and immunofluorescence on osteoclasts, and for in immunofluorescence We of and of Ontario) for on the We Boyle and Dunstan for soluble RANKL and

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.